Self-replication process holds promise for production of new materials

October 12, 2011

New York University scientists have developed artificial structures that can self-replicate, a process that has the potential to yield new types of materials. The work, conducted by researchers in NYU's Departments of Chemistry and Physics and its Center for Soft Matter Research, appears in the latest issue of the journal Nature.

In the natural world, self-replication is ubiquitous in all living entities, but artificial self-replication has been elusive. The discovery in Nature reports the first steps toward a general process for self-replication of a wide variety of arbitrarily designed seeds. The seeds are made from DNA tile motifs that serve as letters arranged to spell out a particular word. The replication process preserves the letter sequence and the shape of the seed and hence the information required to produce further generations.

This process holds much promise for the creation of new materials. DNA is a robust functional entity that can organize itself and other molecules into complex structures. More recently DNA has been used to organize inorganic matter, such as metallic particles, as well. The re-creation by the NYU scientists of this type of assembly in a laboratory raises the prospect for the eventual development of self-replicating materials that possess a wide range of patterns and that can perform a variety of functions. The breakthrough the NYU researchers have achieved is the replication of a system that contains complex information. Thus, the replication of this material, like that of DNA in the cell, is not limited to repeating patterns.

To demonstrate this self-replication process, the NYU scientists created artificial DNA tile motifs short, nanometer-scale arrangements of DNA. Each tile serves as a letterA or Bthat recognizes and binds to complementary letters A' or B'. In the natural world, the DNA replication process involves complementary matches between basesadenine (A) pairs with thymine (T) and guanine (G) pairs with cytosine (C) -- to form its familiar double helix. By contrast, the NYU researchers developed an artificial tile or motif, called BTX (bent triple helix molecules containing three DNA double helices), with each BTX molecule comprised of 10 DNA strands. Unlike DNA, the BTX code is not limited to four lettersin principle, it can contain quadrillions of different letters and tiles that pair using the complementarity of four DNA single strands, or "sticky ends," on each tile, to form a six-helix bundle.

In order to achieve self-replication of the BTX tile arrays, a seed word is needed to catalyze multiple generations of identical arrays. BTX's seed consists of a sequence of seven tilesa seven-letter word. To bring about the self-replication process, the seed is placed in a chemical solution, where it assembles complementary tiles to form a "daughter BTX array"a complementary word. The daughter array is then separated from the seed by heating the solution to ~ 40 oC. The process is then repeated. The daughter array binds with its complementary tiles to form a "granddaughter array," thus achieving self-replication of the material and of the information in the seedand hence reproducing the sequence within the original seed word. Significantly, this process is distinct from the replication processes that occur within the cell, because no biological components, particularly enzymes, are used in its executioneven the DNA is synthetic.

"This is the first step in the process of creating artificial self-replicating materials of an arbitrary composition," said Paul Chaikin, a professor in NYU's Department of Physics and one of the study's co-authors. "The next challenge is to create a process in which self-replication occurs not only for a few generations, but long enough to show exponential growth."

"While our replication method requires multiple chemical and thermal processing cycles, we have demonstrated that it is possible to replicate not just molecules like cellular DNA or RNA, but discrete structures that could in principle assume many different shapes, have many different functional features, and be associated with many different types of chemical species," added Nadrian Seeman, a professor in NYU's Department of Chemistry and a co-author of the study.

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8 comments

Oh great, perhaps their next step might be to create self-replicating robots built to serve man, but who run amok and kill all living things instead. After all, they won't need US any longer.Some of these scientists are more into science fiction than real science that benefits mankind.

Why don't you go complain about messianic endo of the world anti-scientific religions like christianity and even dare I say it? You just know it's socio-politicaly incorrect to say it! The Jews! Why did the Romans go into Palistine to break up the Jews? Why did Josephus decide the Jews were crazy and decide to be Roman? Cause the Jews were messianic end of the worlders!

Both mathematics and mythology are analogies; one is constructive(mathematics) and the other is vague. In Godel's theorems, he says a finite consistent set of axioms cannot prove an infinity of truths; an inconsistent vague set can though! God and those who came up with god beliefs are those who have chosen to go the vague route.

Look what we have here! maxcypher and apparently a bunch of others on a mathematical science website chosing to play stupid!

No max and all the other vagueness gamers, you all represent the end of humanity(since you've chosen to represent the end of scientific curiosity and constructive thought). You are the dark ages.

LOL. . . .once again, I need to remind everyone that I did not start a post on religion or anything resembling it, but I MIGHT reserve the right to answer someone's post on religion issues if I feel that person has problems regarding it. . .as I have done with Nanobanano. I could be mistaken but I read his posts as a plea for help. It takes heart to do that, and I plead guilty on that. But I will post my comment on self-replicating robots built to serve man and the dangers inherent in that and other products capable of self-replication. I respect YOUR views, so please respect mine. Thank you

I don't know your views on religion. I also wasn't argueing against your views on self-replicating nanobots; on that front, you should be happy this is dna-nanotech; all you have to do to pull the plug on them is remove the heat source. I personaly think dna-nanotech is exciting for that very reason; it avoids the problems of daimondoid nanomanufacturing(I've also championed space colonization as a ways of overcoming the problems/dangers of nanomanufacturing; you can make a separate module where the nanomanufacturing goes on; if any outbreak of nanobots is detected, you can just release that nanomanufacturing module; you could have things previously set up to where the momentum sends it into say the sun or a gas giant; or, you could nuke it when it gets to a certain distance; the only problem is what do you do after you've released the magic box for manufacturing everything?) As you can see, I'm not

Well, the wrong kind of technology will have the ability to annihilate the human species if we're not vigilant enough. Scientists are gung ho in general; MAD scientists would be also, but lack the conscience of considering the consequences of the wrong actions. They may get excellent results, but with dire consequences. There needs to be special oversight by federal investigators in these experiments involving self-replication, plus a method of total elimination with the possibility of an accident or deliberately allowing a dangerous event. I agree with you on the special module, but with our present technology it would not be feasible to perform nanomanufacturing in low Earth orbit. And on Earth, they would have to take extraordinary precautions so that these objects don't self replicate in a trash bin, for instance, near a heat source if it gets ejected by accident through possible carelessness.

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